The present invention relates to a vacuum filling machine and method for filling a porous pouch with a microporous powder.
Vacuum insulation panels are useful in a variety of environments, and in particular in conjunction with refrigeration apparatus in which they are utilized as insulating panels in the walls of refrigerators and freezers.
Typically a vacuum insulation panel has some type of insulating material, generally powders or microporous sheets of insulating material which are placed into a non-porous bag and, after evacuation of all gases, the bag is sealed. Such panels and a method for fabricating them are disclosed in U.S. Pat. No. 5,018,328, assigned to Whirlpool Corporation, the assignee of the present application, the disclosure of said patent being incorporated herein by reference, as well as in U.S. Pat. Nos. 5,076,984 and 4,683,702.
The use of a gas permeable enclosure to contain the powder during evacuation is disclosed in the '984 and '702 patents listed above.